Remember that famous scene in 3x11 where Klaus gives Caroline that speech about the beauty of the world? Everyone focused so much on the poetic, inspiring part of it that we completely overlooked the fact Klaus admited to being suicidal in the past.

His first actual conversation with Caroline, and he says he used to think about killing himself. The gravity of what he a dit just hit me, and I can't even believe it. My mind is blown. He was always so adament on only displaying his strengths to people, appearing all-powerful, even to his family. And then he tells some dying vampire he barely knows...